Animus feeds on anger and hatred. It can amplify these emotions in others, though it prefers receiving over giving. It can metamorphose into any humanoid form and is immune to most physical harm. It can immerse victims in complex illusionary worlds. It can be temporarily destroyed by consuming too much hatred too quickly. Animus is a skilled orator, especially in promoting anger and hatred, and manipulates others to accumulate resources.

Animus' origins are not revealed: it may be a mutant or mutated human, the spawn of the cosmic Lord Chaos or Master Hate, or something else altogether. In its first recorded activity as the Hate-Monger, it provided advanced weaponry and costumes to Leonard Kryzewski, convincing him to regather the Sons of the Serpent to spread hatred and violence throughout New York City. The Avengers and New Warriors opposed the Sons, and the Hate-Monger escalated tensions into violence between all groups. In a later conflict, the Hate-Monger faded away when Captain America convinced the heroes to overcome their hatred, but it warned them it would be back when their resolve faded and hatred flourished in their hearts. The Hate-Monger next appeared in the Los Angeles riots. After the riots, it targeted Nomad (Jack Monroe), inflaming conflicts with supporters of the homophobic broadcaster the Roar, the HIV injecting Needle, and Texas Senator Hugh Greider. It eventually confronted Nomad directly, even using his infant ward Bucky (Julia Winter) against him, but Nomad ended the conflict by refusing to fight the Hate-Monger.

Returning to L.A., the Hate Monger supplied high-tech weapons to street gang the War Machines. After being assaulted and warned away from the gang by War Machine, the Hate-Monger led the Sons of the Serpent to purchase weapons from A.I.M. and Hydra and use them against streets gangs, such as the War Machines, resulting in another conflict with War Machine. Rhodes framed the Sons as having betrayed A.I.M. and Hydra, turning both groups against the Sons, and the Hate-Monger fled. It next assaulted the hero Justice, exploiting Justice and his mother's hatred of Vance for having accidentally killed his own abusive father. When Norma forgave Vance, and enabled him to get over his self-loathing, the Hate-Monger was foiled. Re-naming itself Animus, it fed off tensions among the Hulk, Bruce Banner, Angela Lipscombe, and Doc Samson. When Animus confronted them directly, Banner used his own hatred to overload and consume Animus, though Animus soon re-formed and prepared for dessert.